Yo-yos have been a toy for children and adults for many years. The general shape of the yo-yo, consisting of two circular discs, attached at their center by a reduced diameter axle has been the general configuration by which they have been known. There has been improvements made to the basic configuration, largely decorative but also in some measures attempting to improve the performance. For example, Ennis in U.S. Pat. No. 4,130,962, disposes the weight of the yo-yo in the periphery of the disks of the toy. Here, Ennis provides the yo-yo with a flywheel effect by placing the weight of the yo-yo near its periphery. Ennis also describes cone-shaped protuberances with rounded ends situated circularily on the inside spaces of the disks proximate the central axle where the rounded tipped protuberances snare loose strands of the yo-yo string for wind-up.
Also, Russell, in U.S. Pat. No. 3,643,373, describes a yo-yo with specially designed disks such that appealing visual effects are obtained when the toy is spinning or in an inoperative position.
One shortcoming of the present state of the yo-yo art is that the string of the yo-yo engages directly the central shaft and thereby incurs weakening abrasions when the yo-yo is placed into its tricks utilizing the yo-yo spinning at the end of the string. Consequently, it is common for the strings of yo-yos to break frequently and thus require replacement. Another problem with the present art is the forming of knots about the yo-yo central axle by the string doubling upon itself. This provides a major source of frustration for the beginning player.
In addition, it is a sought after effect to have a yo-yo which tends to spin in its free spinning mode longer than other yo-yos. In fact, contests are held in this regard. The spinning time determined in large part by two factors, the first being the rotational speed which can be imparted to the yo-yo when it unwinds on its string responding to the throwing action by the operator, and secondly, the friction generated by the free spinning yo-yo between the string and the yo-yo central axle at the end of the yo-yo string. Obviously, the strength of the string is a limiting factor as how hard the yo-yo may be thrown, and the gradual weakening of the string due to the abrasive friction tends to reduce the strength of the string.
Another difficulty with the present art yo-yos are that in attempting to throw the yo-yo into a free spinning configuration, the yo-yo has a tendency to bounce back when it reaches the end of the yo-yo string, gathering string as it goes and then continue to retract to the operator's hand. In addition, when an operator is performing tricks and the tricks are of the type where you have multiple strings between the faces of the spinning yo-yo, i.e., where the yo-yo string is doubled or tripled back upon itself between the yo-yo halves while the yo-yo continues to spin, premature retrieval is of greater likelihood because of the increased friction between the strings and the yo-yo resulting in the yo-yo catching the string and returning to the operator.
Thus, it is apparent there is a desire for an enhanced time of free spinning to perform yo-yo tricks and to better enjoy the toy.